Systems and methods for providing an insulated sleeping chamber

ABSTRACT

A sleeping chamber uses a double-wall inflatable structure to provide insulation against cold temperatures using a non-rigid form constructed of a lightweight material such as a polyethylene film. The sleeping chamber is lighter in weight, smaller in bulk, and generally lower in cost than a conventional tent, while providing improved insulation against cold temperatures.

BACKGROUND OF THE INVENTION

1. Related Applications

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 60/840,388 filed Aug. 25, 2006, entitled INSULATED SLEEPINGCHAMBER, and to U.S. Provisional Patent Application Ser. No. 60/914,661filed Apr. 27, 2007, entitled SYSTEMS AND METHODS FOR PROVIDING ANINSULATED SLEEPING CHAMBER, which are incorporated herein by reference.

2. Field of the Invention

The present invention relates to sleeping chambers. More particularly,embodiments of the present invention relate to a lightweight, non-rigid,highly portable sleeping chamber that provides insulation against lowtemperatures and other environmental dangers even in relatively extremeconditions.

3. Background and Related Art

Products currently exist that provide protection from the elements whensleeping outside of a dwelling, such as when camping or duringemergencies (e.g., natural disasters or when stranded away from safedwelling places). One example of such a product is a tent. Tents areavailable in a variety of shapes and sizes, with features suited to avariety of conditions. Tents include rigid structures to create a cavitywithin which a person may repose, generally within a sleeping bag tostay warm. While some tents rely on a set of flexible rigid poles toprovide a pop-up design requiring limited assembly time, most tentsrequire efforts such as staking corners of the tent into the ground,positioning tent poles, and so forth. Generally, those devices which aremost convenient to use are also very expensive to produce and purchase.

Many situations arise, however, where tents are inadequate. Theseinclude situations where the bulk of a tent is inappropriate, where theweight of a tent is unacceptable, or where the cost of a tent isprohibitively high. Nevertheless, persons in such situations may requireprotection from the elements and the ability to sleep in comfort.

Thus, while techniques currently exist that are used to provideprotection from the elements, challenges still exist. Accordingly, itwould be an improvement in the art to augment or even replace currenttechniques with other techniques.

SUMMARY OF THE INVENTION

The present invention relates to sleeping chambers. More particularly,embodiments of the present invention relate to lightweight, non-rigid,highly portable sleeping chambers that provide insulation against lowtemperatures and other environmental dangers even in relatively extremeconditions.

Implementation of the present invention takes place in association witha sleeping chamber having a double-wall inflatable structure to provideinsulation against cold temperatures using a non-rigid form constructedof a lightweight material such as a polyethylene film. The sleepingchamber is lighter in weight, smaller in bulk, and generally lower incost than a conventional tent, while providing improved insulationagainst cold temperatures.

While the methods and processes of the present invention have proven tobe particularly useful in the area of individual sleeping chambers,those skilled in the art can appreciate that the methods and processescan be used in a variety of different applications.

These and other features and advantages of the present invention will beset forth or will become more fully apparent in the description thatfollows and in the appended claims. The features and advantages may berealized and obtained by means of the instruments and combinationsparticularly pointed out in the appended claims. Furthermore, thefeatures and advantages of the invention may be learned by the practiceof the invention or will be obvious from the description, as set forthhereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the manner in which the above recited and other featuresand advantages of the present invention are obtained, a more particulardescription of the invention will be rendered by reference to specificembodiments thereof, which are illustrated in the appended drawings.Understanding that the drawings depict only typical embodiments of thepresent invention and are not, therefore, to be considered as limitingthe scope of the invention, the present invention will be described andexplained with additional specificity and detail through the use of theaccompanying drawings in which:

FIG. 1 illustrates a representative embodiment of the present inventionhaving a flexible arm;

FIG. 2 illustrates a cross-sectional view of the representativeembodiment illustrated in FIG. 1;

FIG. 3 illustrates a top view of the representative embodiment of FIG.1;

FIG. 4 illustrates a side view of the representative embodiment of FIG.1;

FIG. 5 illustrates another embodiment of the present invention;

FIG. 6 illustrates another representative embodiment of the presentinvention;

FIG. 7 illustrates as side view of another representative embodiment ofthe present invention;

FIG. 8 illustrates a top view of another representative embodiment ofthe present invention;

FIG. 9 illustrates a side view of another representative embodiment ofthe present invention;

FIG. 10 illustrates a top view of another representative embodiment ofthe present invention;

FIG. 11 illustrates a side view of another representative embodiment ofthe present invention;

FIG. 12 illustrates a front view of another representative embodiment ofthe present invention;

FIG. 13 illustrates a top view of the representative embodiment of FIG.12;

FIG. 14 illustrates a side view of the representative embodiment of FIG.12;

FIG. 15 illustrates a front view of another representative embodiment ofthe present invention;

FIG. 16 illustrates a top view of the representative embodiment of FIG.15; and

FIG. 17 illustrates a side view of the representative embodiment of FIG.15.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to sleeping chambers. More particularly,embodiments of the present invention relate to lightweight, non-rigid,highly portable sleeping chambers that provide insulation against lowtemperatures and other environmental dangers even in relatively extremeconditions.

With reference to FIG. 1, a representative embodiment of the presentinvention is illustrated as substantially non-rigid structure 10 havingat least one inflatable space 30 capable of retaining gas or air. Insome embodiments, non-rigid structure 10 comprises an elongate tunnel 20and a hood 50, wherein tunnel 20 is capable of substantially enclosingat least one occupant 5, and tunnel 20 is closed on one end 42 and openon the other end 44.

In some embodiments, two layers (illustrated as layers 26 and 28) thatare not required to be constructed of the same material, are used toconstruct the top 22 of tunnel 20 and to cause tunnel 20 to retain aconcave or tunnel-like shape when inflatable space 30 filled with a gasor air. The two layers 26, 28 are sealed or otherwise coupled togetherto create at least one inflatable space 30 capable of retaining a gas(e.g., ambient air, etc.), thus forming a dead air space when inflated.

In some embodiments, an inflation valve 46 provides access to inflatablespace 30 so that a user can inflate space 30 by blowing air into valve46, which may be positioned inside tunnel 20, outside tunnel 20, orotherwise, as will be apparent to those skilled in the art. In someembodiments, valve 46 is designed or otherwise intended for use with anaccessory air pump. In some embodiments, tunnel 20 includes, whetherintegrated or as an accessory, containers of compressed gasses ofvarious types capable of automatically inflating inflatable space 30.

When the inflatable space 30 is not inflated, the materials comprisingtunnel 20 can be substantially flat, without a tunnel-like shape orform, and are capable of being folded, rolled, or otherwise greatlyreduced in volume.

In some embodiments, layers 26 and 28 of material that form top 22 oftunnel 20 are spot welded at intermittent points 32 to create a quiltingor waffle-like pattern that aids in holding the position of the twolayers 26, 28 of material in relative positions to one another. By usinga waffled design, top 22 of tunnel 20 retains an enhanced shape wheninflated via inflatable space 30.

In some embodiments, tunnel 20 comprises a height of approximately twofeet or twenty-four inches when inflated with a first dead air spaceformed by inflatable space 30 comprising approximately one toone-and-one-half inches between layers 26 and 28 of material comprisingtop 22 of tunnel 20. In some embodiments, a waffling of layers 26 and 28comprises connected points (e.g., quilt points, weld points, etc.) 32two layers 26, 28 of top 22 that are spaced approximately two inchesfrom one another.

Tunnel 20 also comprises a bottom 24. Bottom 24 may comprise one or morelayers of material that can be the same or may differ from the materialused to construct top 22. In some embodiments, bottom 24 comprises twolayers 34, 36 of material that may be sealed together to form a pocket38, which may be separate from inflatable space 30. Such a pocket 30formed in bottom 24 may comprise a large slit 41 at one end so as topermit the insertion of a mat 40, foam pad, or other material to act asan insulating material between a person lying in sleeping chamber 10 andthe ground on which sleeping chamber 10 may be placed. In someembodiments, pocket 38 may comprise a complete seal at its perimeter,having a valve that permits inflation of the pocket 38 in a mannersimilar to or different from the method used to inflate inflatable space30 in top 22. By inflating pocket 38, an additional dead air space maybe provided to insulate the occupant 5 of sleeping chamber 10 from theground and to provide additional comfort compared to lying on the groundalone.

In some embodiments, the structure and cut of the materials comprisingtunnel 20 is such that when inflatable space 30 is inflated, the bottom24 curves at its open end 44 in a generally upward or cupping shape 43so as to prevent water from easily entering tunnel 20, thus aiding thecomfort of occupant 5. In some embodiments, this cupping shape 43 mayextend approximately four to five inches above the ground.

Tunnel 20 may be affixed to the surface on which it lays, such as theground when camping, by means of one or more optional loops 63 affixedto the sides of tunnel 20 along its length. As one non-limiting example,stakes, as are known in the art, may be inserted through such loops 63and driven into the ground to retain the position of sleeping chamber 10during sleep when winds or sloping terrain might otherwise causeundesired movement.

In some embodiments, sleeping chamber 10 further comprises a hood 50.Hood 50 is typically made of a material similar to that of the tunnel,having characteristics such as puncture resistance, tear resistance, andwater-resistance. The materials used for hood 50 may differ from thoseused for tunnel 20 according to the desired requirements andcharacteristics of sleeping chamber 10. For example, while a coloredmaterial may be used for tunnel 20, a transparent material may be usedfor hood 50. Or, a heavier grade material may be used for tunnel 20 toprovide greater strength, while a lighter grade material may be used forhood 50 to provide lighter weight.

In some embodiments, hood 50 is attached to bottom 24; a portion of thematerial comprising hood 50 may be merely an extension of the materialused to construct a portion of tunnel 20.

In some embodiments, a part of hood 50 may be constructed of at leasttwo layers 52, 54, in the same manner as top 22 of tunnel 20, and sealedso as to create an inflatable space 56 capable of retaining a gas. Bymeans of a valve 48 affixed adjacent to space 56, a user may inflatespace 56 by blowing into it, or by use of a pump, compressed gas device,or otherwise. Once space 56 is inflated, hood 50 may be rotated intoplace as shown in FIG. 1 over the open end 44 of tunnel 20 so as toenclose the open end 44 and provide substantially complete protectionfor occupant 5.

In some embodiments, hood 50 has a height of approximately thirty inchesso as to provide a comfortable headspace for occupant 5. Smaller orlarger spaces may also be created by adjusting the inflation of space 56or by using differing amounts of materials to create hood 50.

Typically, the edge of hood 50 sits on or overlaps with the edge 60 oftop 22 of tunnel 20. In some embodiments, hood 50 may be attached totunnel 20 by any means known in the art, including by means of one ormore Velcro®-style pads, by a Ziploc®-style closure, by snaps, by hooksand eyelets, by zippers, or otherwise. In some embodiments, hood 50 doesnot form an airtight seal with top 22 of tunnel 20 because of theslightly differing contours of the two structures and because of thewaffling that can be used to construct inflatable space 30 and space 56,which can create a bumpy or irregular surface on either top 22 or hood50. Accordingly, in at least some embodiments, sufficient air can flowbetween tunnel 20 and hood 50 so as to permit occupant 5 to breathcomfortably. In other embodiments, a portion of hood 50 adjacent tospace 56 includes an area of mesh material that directly permits airflow to occupant 5.

In some embodiments, tunnel 20 comprises two areas of dead air space:one between the two layers 26, 28 when inflatable space 30 is inflated,and a second dead air space 62 between the bottom side of top 22 of thetunnel and the top of occupant 5. These two areas of dead air spaceprovide significant insulation against cold temperatures outside ofsleeping chamber 10.

In some embodiments, occupant 5 places a sleeping bag 66 into sleepingchamber 10, with sleeping chamber 10 acting as a one-person tent. Inother embodiments, occupant 5 lies in sleeping chamber 10 with only ablanket, with only the clothing he or she is wearing, or with noclothing, relying on the insulative properties of the dead air spacesjust described as protection against the elements.

In some embodiments, tunnel 20 may be constructed with an internal sockor sleeve 90, which may be constructed of nylon or of any other suitablematerial. Such an internal sleeve 90 may be used as a holder foraccessories comprising various grades of material used to providesleeping chamber 10 with different overall levels of insulation or heatretention. For example, an occupant might select a lightweight insertfor use on a warm night, but might select a much heavier insert for useon a bitterly cold night. In this manner, sleeping chamber 10 incombination with an internal sleeve 90 and a selection of additionalinsert materials may act as a sleeping bag, providing variable levels ofinsulation via both dead air space and traditional insulative materialssuch as goose down, polyfill, or otherwise. In some embodiments, sheetof material may be placed across the open end 44 of tunnel 20, where thesheet has a hole and operates as a gasket enclosing the head or head andshoulders of occupant 5, preventing excess air flow between dead airspace 62 and the space around the head of occupant 5 within hood 50.

Sleeping chamber 10, including tunnel 20 and hood 50, may be constructedof any appropriate material as is known in the art. Typically,characteristics such as light weight, water resistance, wind resistance,low cost, tensile strength, resistance to air penetration, and punctureresistance are desired, though the selection of material based on thesecharacteristics may vary based on the requirements of a particular use.For example, when used for emergency relief situations such as aidingthe survival of earthquake victims in mountainous areas, a material oflower cost can be selected to permit the purchase of a larger number ofsleeping chambers; conversely, a high performance use intended foroutdoor enthusiasts might dictate the best combination of light weightand durability without regard to cost. In some embodiments, a plasticfilm sold under the brand name ForceFlex® is used to construct both thetunnel and the hood. In some embodiments, both tunnel 20 and hood 50 areconstructed using a material having a thickness in the range of 1 mil to4 mils. In some embodiments, various plastic films or metallic films areused, such as Mylar®, polyethylene, and/or others.

Sleeping chamber 10 may be used in any environment where insulationagainst cold temperatures is needed. Non-limiting examples of such usesinclude camping, hiking, snowmobiling, fishing, and hunting; emergencypreparedness; search and rescue operations; natural disaster and similaraid situations; military applications, both purpose-built and emergencyuse; and otherwise.

In some embodiments, the non-rigid and lightweight nature of sleepingchamber 10 permit it to be manually folded or compressed into a verysmall volume. In some embodiments, the entire sleeping chamber comprisesa weight of less than one pound.

While at least some descriptions provided herein relate to a sleepingchamber intended for a single individual, multiple structures andformats are encompassed within the invention.

In some embodiments, sleeping chamber 10 is constructed to a smallersize intended for a child; in some embodiments, a tunnel and hood areconstructed to enclose two or more adults positioned side by side 70, asshown in FIG. 5. Those skilled in the art will appreciate thatembodiments of the present invention embrace even larger sizes,including embodiments that are able to enclose more than two occupants.

In some embodiments, sleeping chamber 10 is constructed wholly in atube-like formation, without a hood 50 (a “single bag embodiment”). Insuch an embodiment, open end 44 of tunnel 20 comprises a closingmechanism, such as, without limitation, Velcro®-style closure,drawstring, Ziploc®-style closure, snaps, zipper, or otherwise. In suchan embodiment, at least one portion of the wall of tunnel 20 comprises amesh or other breathable fabric intended to permit the passage of airinto and out of the portion of tunnel 20 in which occupant 5 reposes, inorder to provide occupant 5 with a supply of fresh air.

In some embodiments such as the single bag embodiment, the closuremechanism extends along the top of tunnel 20 adjacent to the place wherean occupant 5 would enter the sleeping chamber10; the closure mechanismcan also extend along the top and sides of tunnel 20, or along only theside of tunnel 20. When the closure mechanism extends along the side oftunnel 20, its length relative to the length of tunnel 20 can be smallor great depending on the intended use of sleeping chamber 10. Forexample, where sleeping chamber 10 is intended for use in a medicalrescue environment or similar situation where occupant 5 would havedifficulty entering a small opening in tunnel 20, a closure mechanismextending substantially the full length of tunnel 20 may be used.

In some embodiments, as shown in FIG. 6, multiple sleeping chambers maybe arranged in a coordinated fashion, such as in a star or otherconfiguration, with a multi-person hood 80 positioned over the openportion of multiple tunnels, so as to provide an insulated portion oversubstantially all of each individual's body while also providing ashared space where multiple individuals may communicate while positionedwithin their individual tunnels.

The identified features, characteristics, functions, and advantagesdescribed herein are not meant to be limiting in any way. It iscontemplated that one skilled in the art will recognize other apparentfeatures and advantages of the various embodiments of the inventionother than those specifically recited, described, or mentioned herein.Therefore, while an embodiment of the invention comprising a tunnel andhood is specifically described, such descriptions are provided with theintention of encompassing like-systems or like-devices or like-methodsthat may or may not be obvious to one having ordinary skill in the art.At least some embodiments of the present invention embrace a polymermaterial, such as a polyethylene or other polymer material.

With reference now to FIGS. 7-11, representative embodiments of thepresent invention are provided. In particular, FIG. 7 illustrates asside view of a representative embodiment of the present invention. Inthe illustrated embodiment of FIG. 7, the length of the sleeping chamberis approximately 6-7 feet long, 32 inches wide, and 24-30 inches high.However, those skilled in the art will appreciate that embodiments ofthe present invention embrace sleeping chambers that are smaller and/orlarger than the illustrated embodiment. Moreover, embodiments of thepresent invention embrace a variety of sleeping chamber configurations.

FIG. 8 illustrates a top view of a representative embodiment of thepresent invention, FIG. 9 illustrates a side view of a representativeembodiment of the present invention with Velcro® tipped snap downs, FIG.10 illustrates a top view of a representative embodiment of the presentinvention, and FIG. 11 illustrates a side view of a representativeembodiment of the present invention. Those skilled in the art willappreciate that while Velcro® tipped snap downs are included in theillustrated embodiment, other embodiments of the present inventionembrace other types of types of closures, including tie downs, snaps,clips, etc.

At least some embodiments of the present invention embrace a sleepingchamber for outdoor backpackers, hunters, scouts, snowmobilers,emergency sleeping shelters, etc. that provides protection frominclement weather conditions, and at the same time, retain body heat,while providing insulation from cold weather. Some embodiments embracehaving a light weight, low volume sock insert.

With reference now to FIGS. 12-14, another representative embodiment isillustrated. In particular, FIG. 12 illustrates a front or rear view ofanother representative embodiment of the present invention, FIG. 13illustrates a top view of the representative embodiment of FIG. 12, andFIG. 14 illustrates a side view of the representative embodiment of FIG.12. In the illustrated embodiment, the sleeping chamber can beselectively inflated, such as required by the weather.

The illustrated embodiment includes a high tensile strength plasticmaterial. In some embodiments, there are multiple layers that arecoupled together. Examples of coupling techniques include gluing, spotwelding, bonding, and other coupling techniques. In at least someembodiments, the layers/materials are coupled in a “waffle” pattern. Inone embodiment, the “waffling” pattern is in approximately a two-inchpattern that is seal welded around the perimeter. The waffling producesa “quilted” shell that, when inflated, produces a 1.5″ to 2″ dead airinsulation barrier, for example. It also produces a dome shape that canrise at the middle, so as not to come in direct contact with theoccupant. The floor includes a double layer of material. If not quilted,the plastic layers at the opening end of the chamber are open to allowthe insertion of a ground pad, for example, for both comfort andinsulation. When the end is quilted, it includes a separate way toinflate (e.g., via mouth, hand pump, or other technique).

In one embodiment, the dome portion covers the occupant inside, but thefloor extends longer to provide a place where the occupant's head can belocated. In a stored position, the sleeping chamber can be rolled upinto a compact position.

With reference now to FIGS. 15-17, another representative embodiment isillustrated. In particular, FIG. 15 illustrates a front or rear view ofanother representative embodiment of the present invention, FIG. 16illustrates a top view of the representative embodiment of FIG. 15, andFIG. 17 illustrates a side view of the representative embodiment of FIG.15. In the illustrated embodiment, the sleeping chamber can beselectively inflated, such as required by the weather. In someembodiments, the floor of the sleeping chamber is inflatable.

In the illustrated embodiment, the length of the sleeping chamber isapproximately 6-7 feet long, and 5 feet wide. In some embodiments, thedome shape includes a height of 48 inches or more. In at least someembodiments, the need for any poles is eliminated. Further, flaps areprovided for entering and/or exiting the sleeping chamber. The flaps areable to be independently inflated or deflated. Tie straps/mechanisms areprovided for enclosure. Those skilled in the art will appreciate thatwhile Velcro® tipped snap downs are included in the illustratedembodiment, other embodiments of the present invention embrace othertypes of types of closures, including tie downs, snaps, clips, etc. Atleast some embodiments embrace the use of stakes to be secured to theground. In a storage position, the sleeping chamber can be placed into acompact area.

At least some embodiments include venting that allows airflow at thehead, foot, seam and/or surface of a sleeping chamber. Moreover, thoseskilled in the art will appreciate that embodiments of the presentinvention embrace sleeping chambers that are smaller and/or larger thanthe illustrated embodiment. Moreover, embodiments of the presentinvention embrace a variety of sleeping chamber configurations.

Thus, as discussed herein, embodiments of the present invention embracesleeping chambers. More particularly, embodiments of the presentinvention relates to a lightweight, non-rigid, highly portable sleepingchamber that provides insulation against low temperatures and otherenvironmental dangers even in relatively extreme conditions.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges that come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

1. A sleeping chamber comprising: a first non-rigid portion having atleast one inflatable portion capable of being filled with a gas toprovide a first dead air space within said inflatable portion and asecond dead air space between said inflatable portion and an occupant ofsaid sleeping chamber.
 2. The sleeping chamber of claim 1, furthercomprising a second non-rigid portion positioned above the firstnon-rigid portion, wherein the first non-rigid portion isnon-hermetically attached to the second non-rigid portion along asubstantial part of the perimeter of the first non-rigid portion, andwherein the second non-rigid portion is inflatable, and wherein thesecond non-rigid portion comprises multiple layers of a material thatare joined to one another at intervals.
 3. The sleeping chamber of claim2, wherein the material comprises at least one of (i) polyethylene, (ii)Mylar, (iii) thermoplastic films, and (iv) metallic films.
 4. Thesleeping chamber of claim 2, wherein inflation of the second non-rigidportion creates a dead air space within the second non-rigid portion. 5.The sleeping chamber of claim 2, wherein inflation of the secondnon-rigid portion creates a dead air space between the first non-rigidportion and the second non-rigid portion.
 6. The sleeping chamber ofclaim 5, wherein the dead air space is vented to an area not enclosed byeither the first non-rigid portion or the second non-rigid portion. 7.The sleeping chamber of claim 5, wherein the dead air space is capableof enclosing at least one person.
 8. The sleeping chamber of claim 2,wherein the second non-rigid portion is inflated with air.
 9. Thesleeping chamber of claim 2, further comprising a non-rigid inflatablehood hingedly attached to the first non-rigid portion.
 10. A sleepingchamber comprising: a first portion; and a second portion positionedabove the first portion, wherein the first portion is non-hermeticallyattached to the second portion along a substantial part of a perimeterof the first portion, and wherein the second portion is inflatable. 11.A sleeping chamber as recited in claim 10, further comprising: a hoodthat is non-hermetically attached to one end of the first portion,wherein the first portion, the second portion, and the hood eachcomprise a non-rigid, inflatable structure, and wherein when both thefirst portion and the second portion are inflated, a dead air spaceexists between the first portion and the second portion.
 12. Thesleeping chamber of claim 10, wherein the second portion comprisesmultiple layers of a material and the multiple layers are joined to oneanother at intervals.
 13. The sleeping chamber of claim 12, wherein thematerial comprises at least one of (i) polyethylene, (ii) Mylar, (iii)thermoplastic films, and (iv) metallic films.
 14. The sleeping chamberof claim 10, wherein the dead air space is vented to an area notenclosed by either the first portion or the second portion.
 15. Thesleeping chamber of claim 10, wherein the dead air space is capable ofenclosing one person.
 16. The sleeping chamber of claim 10, wherein thedead air space is capable of enclosing multiple persons.
 17. A method ofmanufacturing a sleeping chamber comprising: providing a first non-rigidportion comprising multiple layers of a lightweight material wherein themultiple layers of the first portion are capable of retaining a gas;providing a second non-rigid portion comprising multiple layers of alightweight material wherein the multiple layers of the second portionare capable of retaining a gas; and coupling the second non-rigidportion to the first non-rigid portion along a substantial part of theperimeter of the first non-rigid portion.
 18. The method of claim 17,wherein the multiple layers of the second portion are joined to oneanother at intervals.
 19. The method of claim 17, wherein said couplingcomprises creating a structure such that when the multiple layers of thefirst non-rigid portion are filled with a gas and the multiple layers ofthe second non-rigid portion are filled with a gas, a space existsbetween the first non-rigid portion and the second non-rigid portion,said space being capable of enclosing at least one person.
 20. Themethod of claim 19, wherein said space is vented to an area not enclosedby either the first non-rigid portion or the second non-rigid portion.